Mud saver valve

ABSTRACT

Present embodiments are directed to a mud saver valve assembly having a first sleeve, a second sleeve, and a first valve element axially captured between the first sleeve and the second sleeve, wherein the first valve element includes a support ring portion extending about a circumference of the first valve element and a center portion extending across the support ring portion, wherein the center portion comprises a dome-shaped geometry.

BACKGROUND

Present embodiments relate generally to the field of drilling and processing of wells, and, more particularly, to a mud saver valve for controlling flow of mud or other fluid during insertion of casing elements into a wellbore during drilling and completion operations and the like.

In conventional oil and gas operations, a drilling rig is used to drill a wellbore to a desired depth using a drill string, which includes drillpipe, drill collars and a bottom hole drilling assembly. During drilling, the drill string may be turned by a rotary table and kelly assembly or by a top drive to facilitate the act of drilling. As the drill string progresses down hole, additional tubular (e.g., drillpipe) is added to the drill string. Once the wellbore reaches a desired depth, the drill string may be removed from the wellbore and the completion phase may be initiated. The completion phase includes assembling downhole tubular (e.g., casing) and equipment used to enable production from an oil or gas well. During both drilling and completion phases, tubular may be assembled or coupled together to form tubular strings.

During drilling or completion of the well, the drilling rig may be used to insert joints or stands (e.g., multiple coupled joints) of tubular into the wellbore. As an example, during insertion of tubular into the wellbore by a traditional operation, each tubular element (e.g., each joint or stand) is coupled to an attachment feature, such as an elevator, that is in turn lifted by a traveling block of the drilling rig such that the tubular element is positioned over the wellbore. An initial tubular element may be positioned in the wellbore and held in place by gripping devices, such as slips or a spider, near the rig floor. Subsequent tubular elements may then be aligned with and coupled to the existing tubular elements in the wellbore to continue formation of the tubular string (e.g., casing string or drill string).

Once properly aligned and attached, the tubular element and remaining tubular string may be held in place by an elevator and released from the gripping devices (e.g., slips) such that the completion string can be lowered into the wellbore. Once the completion string is in place, the gripping devices can be reengaged to hold the completion string such that the elevator can be released and the process of aligning and attaching tubular elements can be started again.

During insertion of tubular elements (e.g., casing) into a wellbore during completion operations, a flow of mud or other fluid may be pumped into the tubular elements and wellbore to facilitate the tubular or casing running operation. It is now recognized that certain aspects of these existing techniques are not optimal because of various limitations (e.g., equipment limitations) during certain phases of operation. For example, when a flow of mud or other fluid is circulated, mud or other fluid can inadvertently be spilled onto a rig floor during certain phases of operation. Existing valves to control the flow of mud during insertion and/or removal of tubular elements may be costly, susceptible to wear and corrosion, and so forth.

BRIEF DESCRIPTION

In accordance with one aspect of the disclosure, a system includes a mud saver valve assembly having a first sleeve, a second sleeve, and a first valve element axially captured between the first sleeve and the second sleeve, wherein the first valve element includes a support ring portion extending about a circumference of the first valve element and a center portion extending across the support ring portion, wherein the center portion comprises a dome-shaped geometry.

In accordance with another embodiment of the disclosure, a system includes a casing running tool configured to couple to a casing element and add the casing element from a casing string and a mud saver valve assembly disposed within the casing running tool, wherein the mud saver valve assembly is configured to flow a fluid through the casing running tool and into the casing element, the mud saver valve assembly includes a valve element extending across a flow path of the mud saver valve assembly, and the valve element is formed from an elastomer.

In accordance with a further aspect of the disclosure, a system includes an upper annular sleeve comprising a first axial recess, a lower annular sleeve comprising a second axial recess, a valve element axially captured between the upper annular sleeve and the lower annular sleeve, wherein the valve element includes a support ring extending about a circumference of the valve element, wherein the support ring has a first axial contour and a second axial contour and a dome-shaped center portion extending between the support ring, wherein the first axial contour is disposed within the first axial recess, the second axial contour is disposed within the second axial recess, and the valve element is formed from a rubber.

DRAWINGS

These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

FIG. 1 is a schematic of a well being drilled in accordance with present techniques;

FIG. 2 is a cross-sectional side view of an embodiment of a mud saver valve assembly, in accordance with present techniques;

FIG. 3 is a partial cross-sectional side view of an embodiment of the mud saver valve assembly, illustrating a valve element captured between sleeves of the mud saver valve assembly;

FIG. 4 is s a perspective view of an embodiment of a valve element of a mud saver valve assembly, in accordance with present techniques;

FIG. 5 is a cross-sectional side view of a valve element of the mud saver valve assembly in a closed position, in accordance with present techniques;

FIG. 6 is a cross-sectional side view of a valve element of the mud saver valve assembly in an opened position, in accordance with present techniques; and

FIG. 7 is a schematic side view of an embodiment of a mud saver valve assembly, in accordance with present techniques.

DETAILED DESCRIPTION

Present embodiments are directed to systems and methods for controlling circulation of mud or other fluid within a wellbore during insertion of tubular elements (e.g., casing) into a wellbore during wellbore completion operations and the like. A casing running tool (e.g., tubular running tool) may be used to facilitate assembly and disassembly of casing strings. Indeed, a casing running tool may be employed to engage and lift a tubular element (e.g., a casing joint or element), align the tubular element with a casing string, stab a pin end of the tubular element into a box end of the tubular string, engage the casing string, and apply torque to make-up a coupling between the tubular element and the casing string. Thus, a casing running tool may be employed to extend the tubular or casing string. Similarly, the casing running tool may be used to disassemble tubular or casing elements from a casing string by applying reverse torque and lifting the tubular elements out of the engagement with the remaining casing string. It should be noted that torque may be applied using a top drive system coupled to the casing running tool or integral with the casing running tool.

During a process of installing or removing tubular or casing elements, it may be desirable to circulate fluids (e.g., drilling mud) through the associated casing string. Accordingly, the casing running tool may be configured to create a flow path between the tubular handling equipment and the tubular or casing element such that fluid can efficiently pass from the casing running tool into the tubular element, and thereafter the casing string. In accordance with present embodiments, a flow of mud or other fluid through the tubular elements and within the wellbore may be regulated during insertion of the tubular or casing elements. For example, the flow of mud or other fluid may be automatically enabled when a casing running tool is coupled to a tubular element and/or when a mud pump for pumping drilling mud is in a pumping mode. The flow of mud or other fluid may be blocked when the casing running tool is decoupled from a tubular element or casing string and/or when the mud pump is not in a pumping mode. To this end, present embodiments include a mud saver valve assembly that may be disposed within or coupled to the casing running tool. The mud saver valve assembly includes a valve element configured to block mud or fluid flow when a fluid flow pressure applied to the valve element is below a threshold pressure, while enabling mud or fluid flow when the fluid flow pressure applied to the valve element is above the threshold pressure. For example, the threshold pressure may be equal to or greater than a head pressure of mud or fluid that may be contained in the casing running tool and/or a mud hose when the mud pump is not in a pumping mode. Thus, when the mud pump is not pumping mud or other fluid (e.g., when the casing running tool is not coupled to a tubular element to be added to a casing string), the valve element may block flow of mud or fluid still contained in the casing running tool or mud hose, thereby preventing inadvertent flow of mud from the casing running tool and onto a rig floor or platform. However, when the pressure applied to the valve element is greater than the threshold pressure (e.g., when the mud pump is in a pumping mode as the pipe drive system is coupling a tubular element to the casing string), the valve element enables flow of mud through the casing running tool and into the tubular element and casing string.

Turning now to the drawings, FIG. 1 is a schematic of a drilling rig 10 in the process of drilling a well in accordance with present techniques. While FIG. 1 represents the drilling rig 10 during a drilling and/or completion process, present embodiments may be utilized for disassembly processes and so forth. In particular, present embodiments may be employed in procedures including assembly or disassembly tubular elements, wherein it is desirable to provide and control fluid circulation through the tubular elements from a tubular handling system during assembly procedures.

In the illustrated embodiment, the drilling rig 10 features an elevated rig floor 12 and a derrick 14 extending above the rig floor 12. A supply reel 16 supplies drilling line 18 to a crown block 20 and traveling block 22 configured to hoist various types of equipment and tubular elements above the rig floor 12. The drilling line 18 may be secured to a deadline tiedown anchor. Further, a drawworks may regulate the amount of drilling line 18 in use and, consequently, the height of the traveling block 22 at a given moment. Below the rig floor 12, a casing string 28 extends downward into a wellbore 30 (e.g., a pre-drilled wellbore) and is held stationary with respect to the rig floor 12 by a rotary table 32 and slips 34. A portion of the casing string 28 extends above the rig floor 12, forming a stump 36 to which another tubular element or length of casing 38 is in the process of being added.

The length of casing 38 is held in place by a casing running tool 40 that is hanging from the traveling block 22. Specifically, a gripping device 42 of the casing running tool 40 is engaged about an outer perimeter of a distal end 44 of the casing 38. This attachment via the gripping device 42 enables the casing running tool 40 to maneuver the casing 38. In the illustrated embodiment, the casing running tool 40 is holding the casing 38 in alignment with the stump 36. The gripping device 42 may include an integral seal or may be configured to couple with the casing 38 about a seal such that a sealed passage is established between the casing running tool 40 and the casing 38. Establishing this sealed passage facilitates circulation of fluid (e.g., drilling mud) through the casing running tool 40 into the casing 38 and the casing string 28. Further, the gripping device 42 couples with the casing 38 in a manner that enables translation of motion to the casing 38. Indeed, in the illustrated embodiment, the casing running tool 40 includes a top drive 46 configured to supply torque for making-up and unmaking a coupling between the casing 38 and the stump 36. It should be noted that, in some embodiments, the top drive 46 is separate from the casing running tool 40.

To facilitate the circulation of mud or other drilling fluid within the wellbore 30, the drilling rig 10 includes a mud pump 48 configured to pump mud or drilling fluid up to the casing running tool 40 through a mud hose 50. In certain embodiments, the mud hose 50 may include a stand pipe 52 coupled to the derrick 14 in a substantially vertical orientation to facilitate pumping of mud. The stand pipe 52 provides a high-pressure path for mud to flow up the derrick 14 to the casing running tool 40. From the mud hose 50 (e.g., stand pipe 52), the mud flows through a kelly hose 53 to the casing running tool 40. From the casing running tool 40, the drilling mud will flow through internal passages of the gripping device 42, into internal passages of the casing 38 and the casing string 28, and into the wellbore 30 to the bottom of the well. The drilling mud flows within the wellbore 30 (e.g., in an annulus between the casing string 28 and the wellbore 30) and back to the surface where the drilling mud may be recycled (e.g., filtered, cleaned, and pumped back up to the casing running tool 40 by the mud pump 48).

The illustrated embodiment of the drilling rig 10 further includes a controller 54 having one or more microprocessors 56 and a memory 58. The memory 58 is a non-transitory (not merely a signal), computer-readable media, which may include executable instructions that may be executed by the microprocessor 56. The controller 54 is configured to regulate operation of the mud pump 48 and/or other features of the drilling rig 10. For example, the controller 54 may be configured to regulate a flow rate of mud or other drilling fluid circulated through the casing string 28 and the wellbore 30 during installation of tubular elements (e.g., casing 38). For example, the controller 52 may regulate operation of the mud pump 48 to start, stop, increase, and/or decrease mud flow into the casing string 28 and wellbore 30 during installation of casing 38 elements. The controller 52 may also regulate other components of the drilling rig 10 to control flow of drilling mud. For example, the controller 52 may control operation of the casing running tool 40 and/or a valve disposed along the mud hose 50.

As discussed in detail below, the casing running tool 40 also includes a mud saver valve assembly 60. When a new length of casing 38 is to be added to the casing string 28, mud flow from the pump 48 and the mud hose 50 is stopped, and the casing running tool 40 (e.g., the gripping device 42) is removed from the casing string 28 (i.e., the length of casing 38 most recently added to the casing string 28). When the casing running tool 40 releases the casing string 28, mud within the casing running tool 40 may run out of the casing running tool 40 and onto the rig floor 12. To avoid spilling mud onto the rig floor 12, the casing running tool 40 includes the mud saver valve assembly 60 to block flow of mud from out of the casing running tool 40 when the mud pump 48 is not pumping mud. When the casing running tool 40 is thereafter coupled to a new length of casing 38 and the mud pump 48 resumes a pumping operation, the mud saver valve assembly 60 automatically enables flow of mud through the mud saver valve assembly 60 and the casing running tool 40 to the casing 38 and casing string 28.

As described below, the mud saver valve assembly 60 includes a valve element configured to block mud flow through the mud saver valve assembly 60 when the mud pump 48 is not running (e.g., pumping) and/or when the casing running tool 40 is decoupled from the casing 38 and/or casing string 28. In this manner, the mud saver valve assembly 60 may block mud remaining in the casing running tool 40, kelly hose 53, and/or mud hose 50 (e.g., stand pipe 52) from inadvertently flowing out of the casing running tool 40 and onto the rig floor 12 when the casing running tool 40 is decoupled from the casing 38. When the mud pump 48 is running and pumping a mud flow (e.g., when the casing running tool 40 is coupled to casing 38), the valve element may automatically enable flow of mud through the casing running tool 40 and into the casing 38. For example, the valve element may have a material construction, geometry, and/or shape that enables blockage of mud flow when the mud pump 48 not pumping, while enabling automatic flow of the mud when the mud pump 48 is pumping. As discussed further below, the valve element of the mud saver valve assembly 60 may also be formed from a durable, resilient, corrosion resistant material, thereby enabling improved longevity and useful life of the valve element and the mud saver valve assembly 60.

FIG. 2 is a cross-sectional side view an embodiment of the mud saver valve assembly 60, illustrating a valve element 80 captured between sleeves 82 of the mud saver valve assembly 60. More specifically, the valve element 80 is axially captured between an upper sleeve 84 and a lower sleeve 86. For example, the upper and lower sleeves 84 and 86 may be tubes or annular members, and the valve element 80 may have a generally circular outer diameter. In other embodiments, the upper and lower sleeves 84 and 86 and the valve element 80 may have other geometries (e.g., square, rectangular, polygonal, elliptical, etc.). As mentioned above, the mud saver valve assembly 60 is coupled to (e.g., positioned within) the casing running tool 40. For example, the mud saver valve assembly 60 may be threaded, bolted, clamped, or otherwise mechanically attached to the casing running tool 40. The upper and lower sleeves 84 and 86 generally define a flow path 85 through which a flow of drilling mud or other fluid may flow through the casing running tool 40 and into the casing element 38. When the casing running tool 40 is coupled to a length of casing 38, the mud saver valve assembly 60 is inserted axially into (e.g., “stabbed” into) the casing 38. In this manner, drilling mud may flow from the casing running tool 40, through the mud saver valve assembly 60, as indicated by arrow 88, and into the casing 38 when the mud pump 48 is pumping. As will be appreciated, the mud saver valve assembly 60 and/or the casing running tool 40 may include seals 89 (e.g., O-rings, axial seals, annular seals, etc.), gaskets, and/or other components configured to enable a flow of mud or other fluid through the casing running tool 40, the mud saver valve assembly 60, and the casing 38.

As mentioned above, the valve element 80 is configured to block mud flow through the mud saver valve assembly 60 and, thus, the casing running tool 40 when the mud pump 48 is not pumping, while automatically enabling mud flow through the mud saver valve assembly 60 and, thus, the casing running tool 40 when the mud pump 48 is pumping. To this end, the valve element 80 is formed from a flexible, yet resilient, material. For example, the valve element 80 may be formed from a rubber (e.g., steel-belted rubber), polyurethane, neoprene, other elastomer, or other suitable material. In certain embodiments, the valve element 80 may be a single molded piece. Additionally, to enable blockage of flow and/or retention of mud within the casing running tool 40 when the mud pump 48 is not in a pumping mode, the valve element 80 has a dome-shaped geometry or shape. Details and functionalities of the dome-shaped geometry of the valve element 80 are discussed in further detail below with reference to FIGS. 4-6. The sleeves 82 of the mud saver valve assembly 60 may be formed from any suitable and durable (e.g., corrosion and/or wear resistant) material, such as steel, plastic, or other material.

FIG. 3 is a partial cross-sectional side schematic view, taken within line 3-3 of FIG. 2, of the mud saver valve assembly 60, illustrating axial capture of the valve element 80 between the sleeves 82. The upper and lower sleeves 84 and 86 are coupled to one another, as indicated by arrow 100, with the valve element 80 at least partially between the upper and lower sleeves 84 and 86. In certain embodiments, the upper and lower sleeves 84 and 86 may be coupled to one another via a threaded connection, a shrink fit, an interference fit, bolts, clamps, or other fasteners. In the illustrated embodiment, the upper sleeve 84 is disposed about the lower sleeve 86, but in other embodiments the lower sleeve 86 may be disposed about the upper sleeve 84. In yet another embodiment, the upper and lower sleeves 84 and 86 may at least partially axially abut one another. Furthermore, the upper and lower sleeves 84 and 86 may include seals, gaskets, or other components disposed therebetween to block leakage of drilling mud or fluid from the mud saver valve assembly 60.

As discussed below, the valve element 80 includes a support ring portion 102 (e.g., radially outer ring) and a center portion 104 (e.g., dome-shaped portion). The support ring portion 102 is axially captured and retained between the upper and lower sleeves 84 and 86. To facilitate the axial capture of the valve element 80, the support ring portion 102 has an upper axial contour 106 and a lower axial contour 108. The upper axial contour 106 of the support ring portion 102 is received (e.g., nested within) a corresponding axial recess 110 of the upper sleeve 84 having a similar contour. Likewise, the lower axial contour 108 of the support ring portion 102 is received (e.g., nested within) a corresponding axial recess 112 of the lower sleeve 86 having a similar contour. When the upper and lower sleeves 84 and 86 are coupled to one another, the upper axial contour 106 and the lower axial contour 108 of the support ring portion 102 are captured by the axial recess 110 and the axial recess 112, respectively, thereby securing the support ring portion 102 and, thus, the valve element 80 between the upper and lower sleeves 84 and 86. When the valve element 80 is axially captured by the upper and lower sleeves 84 and 86, the center portion 104 extends across the flow path 85 of the mud saver valve assembly 60.

FIG. 4 is a perspective view of the valve element 80, illustrating the support ring portion 102 and the center portion 104. As described above, the support ring portion 102 is axially captured between the upper and lower sleeves 84 and 86 to secure the valve element 80 within the mud saver valve assembly 60. The center portion 104, which extends between the circular support ring portion 102, is exposed to an interior (e.g., flow path 85) of the mud saver valve assembly 60. Thus, the center portion 104 is exposed to a mud flow within the casing running tool 40.

As mentioned above, in one embodiment, the valve element 80 is formed from a flexible, yet resilient, material, and the center portion 104 has a dome-shaped configuration. The center portion 104 is further divided into sections or segments 120. More specifically, the center portion 104 is cut or sliced to divide the center portion 104 into the segments 120. For example, in the illustrated embodiment, the center portion 104 has two slits 122 extending across a diameter or width of the center portion 104 at approximately 90 degrees relative to one another. As a result, the center portion 104 is divided into four segments 120. Other embodiments of the valve element 80 may include other numbers of slits 122 (e.g., diameter slits and/or radial slits) to divide the center portion 104 into other numbers of segments 120 (e.g., 3, 5, 6, 7, or more segments 120). As will be appreciated, the individual segments 120 may move (e.g., bend) independently from one another.

FIG. 5 is a cross-sectional side view of the valve element 80, illustrating the dome-shaped configuration of the center portion 104. While the flexible, resilient material of the valve element 80 enables deformation (e.g., bending) of the segments 120 of the center portion 104, the dome-shaped configuration of the center portion 104 enables the valve element 80 to withstand a threshold pressure (e.g., stagnant drilling mud in the casing running tool 40 when the mud pump 48 is not pumping mud) without deformation of the segments 120. The number of segments 120, the type of material, the length of the slits 122, the size of the valve element 80, and so forth, may be calibrated based on empirical data to fully/partially open at certain pressures.

A concave side 140 of the center portion 104, which is exposed to the drilling mud flow from the casing running tool 40 (e.g., an upstream direction of the drilling mud flow), may withstand a threshold pressure (e.g., amount of drilling mud) applied to the concave side 140 of the center portion 104 without deforming to the point that the pressure (e.g., drilling mud) traverses or flows past the center portion 104. As will be appreciated, the threshold pressure of the concave side 140 of the center portion 104 may generally correspond to a pressure head of drilling mud that may be within the casing running tool 40, kelly hose 53, and/or stand pipe 52 when the casing running tool 40 is decoupled from the casing string 28 and the mud pump 48 pumping operation is suspended. The particular threshold pressure that the concave side 140 of the center portion 104 can withstand without allowing the pressure to traverse the center portion 104 (e.g., via excessive bending of the segments 120) may be selected by adjusting various design parameters of the center portion 104 and/or the valve element 80. For example, a material of a particular resilience may be selected to manufacture the valve element 80, such that the segments 120 do not deform and open the valve element 80 until a particular pressure applied to the concave side 140 is reached. Additionally, a number of segments 120, a thickness 142, and/or a radius of curvature 144 of the center portion 104 may be selected to achieve a desired pressure withstanding capability of the concave side 140 of the valve element 80. In certain embodiments, parameters of the valve element 80 (e.g., material resilience, number of segments 120, thickness 142, and/or radius of curvature 144) may be selected to achieve a threshold pressure of 50, 60 70, 80, 90, 100, 110, 120 pounds per square inch, or more.

Moreover, pressure (e.g., drilling mud) below the threshold pressure that is applied to the concave side 140 of the center portion 104 may improve a seal created by the center portion 104 when the mud pump 48 is not pumping mud to the casing running tool 40. For example, as indicated by arrows 146, pressure applied to the concave side 140 of the center portion 104 may cause the segments 120 of the center portion 104 to press against one another due to the dome-shaped configuration of the center portion 104. That is, a seal interface 148 (e.g., at slits 122) between adjacent segments 120 may be strengthened, as indicated by arrows 150, as a pressure below the threshold pressure is applied to the concave side 140. In this manner, the sealing capability of the valve element 80 when the mud pump 48 is not pumping mud to the casing running tool 40 may be improved, thereby further reducing inadvertent leaking of mud or fluid out of the casing running tool 40 (e.g., and onto the rig floor 12) when the casing running tool 40 is decoupled from the casing 38 or casing string 28.

As the valve element 80 and mud saver valve assembly 60 are oriented such that the concave side 140 of the center portion 140 is exposed to the flow of drilling mud within the casing running tool 40, the convex side 152 of the center portion 104 is exposed to the interior of the casing 38 and/or casing string 28 when the casing running tool 40 is coupled to the casing 38 and/or casing string 28. In other words, the convex side 152 is exposed to a downstream side of the mud saver valve assembly 60 relative to a drilling mud or fluid flow. As will be appreciated, the segments 120 will more readily and easily deform (e.g., bend) upon application of a pressure to the center portion 104 from the convex side 152. This may provide additional benefits. For example, the ability of the segments 120 to more easily deform when a pressure 154 (e.g., backpressure within the casing string 28) is applied to the convex side 152 of the valve element 80 may facilitate pressure equalization across the valve element 80.

FIG. 6 is a cross-sectional side view of the valve element 80, illustrating deformation of the segments 120 of the center portion 104 of the valve element 80 when a pressure greater than the threshold pressure is applied to the concave side 140 of the center portion 104. As discussed above, the threshold pressure that the concave side 140 of the center portion 104 may withstand and remain sealed may correspond to a pressure head of drilling mud that may be within the casing running tool 40, kelly hose 53, and/or stand pipe 52 when the casing running tool 40 is decoupled from the casing string 28 and the mud pump 48 pumping operation is suspended. However, when the mud pump 48 pumping operation resumes (e.g., when the casing running tool 40 is coupling another length of casing 38 to the casing string 28), the pressure of the drilling mud on the concave side 140 may exceed the threshold pressure, thereby causing the segments 120 to bend (e.g., invert) and, thus, open the valve element 80 to allow flow of drilling mud from the casing running tool 40 and into the casing 38 and casing string 28. After the casing 38 is added to the casing string 28 and another length of casing 38 is to be added, the mud pump 48 pumping operation may be suspended, thereby dropping the pressure applied to the concave side 140 of the center portion 104, and the segments 120 may revert back to their natural or normal shape, as shown in FIG. 5, to close the valve element 80. In this manner, inadvertent flow of drilling mud from the casing running tool 40 (e.g., onto the rig floor 12) may be blocked when the casing running tool 40 is not coupled to casing 38 to be added to the casing string 28.

In certain embodiments, the mud saver valve assembly 60 may include more than one valve element 80. For example, FIG. 7 is a schematic side view of an embodiment of the mud saver valve assembly 60 having two valve elements 80 (e.g., a first valve element 180 and a second valve element 182) disposed in series with one another. Other embodiments of the mud saver valve assembly 60 may have other numbers (e.g., 3, 4, 5, or more) of valve elements 80. Additionally, the respective orientations of the valve elements 80 may vary. For example, one embodiment having two valve elements 80, the concave side 140 of one valve element 80 may face an upstream direction, and the concave side 140 of a second valve element 80 may face a downstream direction. For example, the concave side 140 of the first valve element 180 may face an upstream direction, and the concave side 140 of the second valve element 182 may face a downstream direction, or vice versa.

The illustrated mud saver valve assembly 60 includes the upper and lower sleeves 84 and 86 and also an intermediate sleeve 184. The first valve element 180 is axially captured by the upper sleeve 84 and the intermediate sleeve 184, and the second valve element 182 is axially captured by the intermediate sleeve 184 and the lower sleeve 86. As will be appreciated, the first and second valve elements 180 and 182 may have similar features as the valve element 80 described above. In certain embodiments, the first and second valve elements 180 and 182 may be designed to have the same threshold pressure, while in other embodiments the first and second valve elements 180 and 182 may be designed to have different threshold pressures. For example, in one embodiment, the first valve element 180 may have a first threshold pressure, and the second valve element 182 may have a second threshold pressure that is lower than the first threshold pressure of the first valve element 180. Additionally, the upper sleeve 84, lower sleeve 86, and intermediate sleeve 184 may have similar features as the upper and lower sleeves 84 and 86 described above.

As discussed in detail above, present embodiments include the mud saver valve assembly 60, which may be used with the casing running tool 40 or other component of the drilling rig 10. The mud saver valve assembly 60 is configured to automatically enable the flow of mud or other fluid through the casing running tool 40 when the casing running tool 40 is coupled to the casing element 38 and/or when the mud pump 48 is in a pumping mode (e.g., during a casing running operation). The mud saver valve assembly 60 is further configured to block the flow of mud or other fluid through the casing running tool 40 when the casing running tool 40 is decoupled from the casing element 38 or the casing string 28 and/or when the mud pump 48 is not in a pumping mode. The mud saver valve assembly 60 includes the valve element 80, which is configured to block mud or fluid flow when a pressure applied to the valve element 80 is below a threshold pressure, while automatically enabling mud or fluid flow when the pressure applied to the valve element 80 is above the threshold pressure. For example, the threshold pressure may be equal to or greater than a head pressure of mud or fluid that may be contained in the casing running tool tem 40 and/or a mud hose 50 when the mud pump 48 is not in a pumping mode. Thus, when the mud pump 48 is not pumping mud or other fluid (e.g., when the casing running tool 40 is not coupled to the casing element 38 to be added to the casing string 28), the valve element 80 may block flow of mud or fluid still contained in the casing running tool 40 and/or mud hose 50, thereby blocking inadvertent flow of mud from the casing running tool 40 and onto the rig floor 12. However, when the pressure applied to the valve element 80 is greater than the threshold pressure (e.g., when the mud pump 48 is in a pumping mode as the casing running tool 40 is coupling the casing element 38 to the casing string 28), the valve element 80 automatically enables flow of mud through the casing running tool 40 via deformation (e.g., bending or inverting) of the segments 120 of the valve element 80.

Embodiments of the valve element 80 described above provide additional improvements over exiting mud saver valves. For example, the valve element 80 may be formed from a durable, corrosion resistant, resilient, and wear resistant material, such as rubber, neoprene, or other elastomer. Thus, the valve element 80 may be less costly to produce, while also providing increased useful life. Moreover, the dome-shaped configuration of the valve element 80 enables the valve element to withstand a threshold pressure (e.g., head pressure of mud within the pipe drive system 40 and/or mud hose 50) in a first direction (e.g., direction of mud flow), while also enabling the valve element 80 to equalize pressure across the mud saver valve assembly 60 in a second direction (e.g., to accommodate backpressure within the casing string 28).

While only certain features of the present disclosure have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the present disclosure. 

1. A mud saver valve assembly, comprising: a first sleeve; a second sleeve; and a first valve element axially captured between the first sleeve and the second sleeve, wherein the first valve element comprises: a support ring portion extending about a circumference of the first valve element; and a center portion extending across the support ring portion, wherein the center portion comprises a dome-shaped geometry.
 2. The mud saver valve assembly of claim 1, wherein the center portion comprises a concave side, and the concave side faces an upstream direction with respect to a fluid flow received by the mud saver valve assembly.
 3. The mud saver valve assembly of claim 1, wherein the center portion comprises a plurality of segments divided by a plurality of slits extending axially through the center portion.
 4. The mud saver valve assembly of claim 3, wherein the plurality of segments comprises four segments, and the plurality of slits comprises two slits, wherein each of the two slits extends across a diameter of the center portion, and the two slits are generally perpendicular to one another.
 5. The mud saver valve assembly of claim 1, wherein the first sleeve and the second sleeve axially capture the support ring portion of the first valve element.
 6. The mud saver valve assembly of claim 1, wherein the first valve element is formed from a rubber, neoprene, or other elastomer.
 7. The mud saver valve assembly of claim 6, wherein the first sleeve and the second sleeve are formed from a steel.
 8. The mud saver valve assembly of claim 1, wherein a concave side of the center portion is calibrated to support a threshold pressure without deformation, wherein the threshold pressure is equal to or greater than a head pressure of fluid within a casing running tool, a head pressure of fluid within a portion of a mud hose of a drilling rig, or any combination thereof.
 9. The mud saver valve assembly of claim 1, comprising a third sleeve and a second valve element, wherein the second valve element is self-similar to the first valve element, and the second sleeve and the third sleeve axially capture the second valve element.
 10. A system, comprising: a casing running tool tem configured to couple to a casing element and add the casing element to a casing string; and a mud saver valve assembly disposed within the casing running tool, wherein the mud saver valve assembly is configured to flow a fluid through the casing running tool and into the casing element, the mud saver valve assembly comprises a valve element extending across a flow path of the mud saver valve assembly, and the valve element is formed from an elastomer.
 11. The system of claim 10, wherein the elastomer comprises rubber, neoprene, or a combination thereof.
 12. The system of claim 10, wherein the mud saver valve assembly comprises an upper sleeve and a lower sleeve, the upper and lower sleeves define the flow path, and the upper and lower sleeves axially capture the valve element.
 13. The system of claim 10, wherein the valve element comprises a dome-shaped configuration.
 14. The system of claim 13, wherein a concave side of the valve element is exposed to an upstream side of the mud saver valve assembly relative to flow of the fluid.
 15. The system of claim 10, wherein the valve element comprises a support ring portion extending about a circumference of the valve element and a center, dome-shaped portion extending between the support ring portion, wherein the support ring portion is axially captured between first and second annular sleeves of the mud saver valve assembly.
 16. The system of claim 15, wherein the center, dome-shaped portion of the comprises a plurality of segments divided by a plurality of slits extending axially through the center, dome-shaped portion, wherein each of the plurality of segments is configured to move independently of one another.
 17. The system of claim 10, wherein the valve element is configured to remain in a closed position upon application of a first pressure and automatically actuate to an open position upon application of a second pressure, wherein the first pressure is below a threshold pressure, and the second pressure is above the threshold pressure.
 18. The system of claim 17, wherein the threshold pressure is greater than a head pressure of fluid within the casing running tool, a head pressure of fluid within a mud hose coupled to the casing running tool, a head pressure of fluid within a stand pipe portion of the mud hose, a head pressure of fluid within a kelly hose of the mud hose, or any combination thereof.
 19. A mud saver valve system, comprising: an upper annular sleeve comprising a first axial recess; a lower annular sleeve comprising a second axial recess; a valve element axially captured between the upper annular sleeve and the lower annular sleeve, wherein the valve element comprises: a support ring extending about a circumference of the valve element, wherein the support ring comprises a first axial contour and a second axial contour; and a dome-shaped center portion extending between the support ring, wherein the first axial contour is disposed within the first axial recess, the second axial contour is disposed within the second axial recess, and the valve element is formed from a rubber.
 20. The mud saver valve system of claim 19, wherein the center portion comprises a plurality of segments formed by a plurality of slits extending axially through the center portion, and a concave side of the center portion faces the upper sleeve. 